Metro Ethernet networks are becoming the choice of service providers for aggregation networks, often using virtual services such as Ethernet virtual connections (EVCs) as a new infrastructure that scales beyond 4K (4096) virtual services. To improve network availability, EVCs are typically provisioned with multiple redundant paths through the networks. One problem with current protocols that attempt to control EVCs, however, is that even if a redundant path is inactive, EVC traffic still floods over it, wasting network bandwidth. For instance, current Virtual Local Area Network (VLAN) based pruning protocols such as MVRP (Multiple VLAN Registration Protocol) and VTP (VLAN or Virtual Trunking Protocol) do not solve this problem because EVC has a finer granularly beyond a single VLAN, and also supports more than 4K services.
Typically, aggregation networks are interconnected through backbone networks, for example, executing IEEE 802.1ah or Multi-Protocol Label Switching (MPLS) technologies. In a single aggregation network, multiple gateway switches (or gateway ports of a single switch) may be utilized to access the backbone network, which can provide redundancy and load balancing. In order to prevent loops and wasted bandwidth, an EVC generally takes only one gateway from the aggregation network to the backbone network, and paths to other gateways should be pruned (removed/blocked). Due to performance and administrative concerns, however, protocols used in the aggregation networks (e.g., their messages, or Bridge Protocol Data Units, “BPDUs”) are not always allowed to tunnel/traverse through the backbone networks. Accordingly, it has generally been difficult (or not possible) to efficiently manage the selection of an active gateway for EVCs, as well as to converge EVC topology based on changing gateway status.